To be "reactionary" is a politics we've long associated (correctly) with the political right. Reactionary politics is defined by a drive not to push towards something, but to eliminate changes and return to some (real or imagined) past. As a result, politics take on not an affirmative character ("this is our vision for where we have to get to") but a negative one - a politics defined by responding negatively to the change of the moment.
Right wing reactionaries are a given - it is endemic to the conservative mode of thought. The greatest impediment to progress from the left isn't right-leaning reactionaries but left-leaning ones. Nominally "progressive" liberals who, out of fear or partisanship or both, turn themselves into "anti-Republicans" without goals, agendas, or theories of change. These are replaced instead by an endless game of political chess with moves and countermoves. To the left-reactionary, an insurgent candidacy of a left wing primary challenger is not "progress," it is taking an unnecessary risk in the ongoing fight against the old enemy.
The goals of the progressive left - though usually given lip service by the reactionary left - are to them secondary to the victory over that enemy and the fear of that enemy's continued dominance."We will get to those things when we've won" they say. But of course what they fail to realize is the truism best expressed in that old Nietzsche quote "Whoever fights monsters should see to it that in the process he does not become a monster." - of course it is more expedient to tilt our politics ever-rightward in order to capture the votes of those centrist reactionaries who desire most of all for things to remain the same and to be left alone -- the radical centrist who fears change and conflict most of all is the greatest ally to reactionary politics and is easily manipulated by the right wing because all progress is change and the right can always promise a "return". But it will tilt us ever rightward, even as we clad ourselves in the language of revolution and "wokeness", every day without an affirmative agenda is another day we slide further into a null, reactionary posture that can easily be shaped by those who already have power and want nothing more than a squabbling, ineffectual body politic.
I’m not talking specifically about Anti-Trumpism here, but the larger context of Anti-Trumpism is a really clear lens to view this from: the delusion that the pandemic, the uprising, the underlying conditions of precarity, inequality, and oppression that brought us to where we are will all change given the removal of Trump is top line magical thinking. Some will say, “well, I understand these things won’t change, but it’s a necessary first step and morale is important”, but of course this is always what is said. That’s the entire raison d'etre of the reactionary left - to cool revolutionary fervor and replace it with harmless partisanship. We see it in the ongoing efforts to rehabilitate warmongering monsters like George W. Bush and John Bolton in the public eye. The lionization of Ruth Bader Gisburg. The strange and ongoing cult of Hillary Clinton. The bizarre glee of some liberals celebrating McGrath’s victory over Charles Booker.
People who espouse this ideology aren’t evil, but ironically, their belief that some are is their cardinal sin. If the fundamental logic error in conservative thinking is that some people are better and more deserving than others, then it is the same sin reflected in reactionary liberals who decide their political quest is a moral one against malicious evildoers. Good does not need a goal outside of defeating evil. Their quest becomes a restoration of order that comes when the bad guy is slain. No systems to dismantle, no powerful forces at work behind every “bad guy” - simply bad actors with bad intentions who require rooting out to restore the rightful order of things. Real fairy tale shit.